The scientific literature provides some examples of photo-induced reduction. One may in particular quote the following articles:
—D. A. S. Finden, E. Tipping, G. H. M. Jaworski and C. S. Reynolds, Nature, Vol. 309, 28 Jun. 1984—; —G. K. Oster, G. Oster, J. Am. Chem. Soc. 1959, 81, 5543; E. L. Wehry, R. A. Ward, Inorg. Chem., 1971, 10, 12, 2660—; —B. C. Faust and R. G. Zepp, Environ. Sci. Technol. 1993, 27, 2517—; —J. Sima and J. Makanova, Coordination Chemistry Reviews, 160, 1997, 161—; —L. Emmenegger, R. Schonenberger, L. Sigg and B. Sulzberger, Limnol. Oceanogr., 46(1), 2001, 49—; et—J. Sima, L. Horvathova, M. Izakovic, Monat. Chem., 2004, 135, 5—.
Nonetheless, none of the described systems presents a sufficient stability that would allow using it both in solution and/or in the solid state.